JPH01129981A - Method for metallizing enamel strongly bonded state and metallized enamel - Google Patents

Abstract

PURPOSE: To easily and tightly metallize enamel by treating the surface of the enamel with ultrasonic waves while roughening it and then carrying out conditioning with a wetting agent, activation and chemical metallizing in order.

CONSTITUTION: The surface of enamel work of an arbitrary shape is mechanically and/or chemically roughened. During or after this roughening, the surface is treated with ultrasonic waves from an ultrasonic wave generator to remove loose materials from the surface. The surface is then subjected to conditioning with an about 1% soln. of an anionic, cationic or nonionic wetting agent, activation with Pd nuclei, at about 40°C and chemical metallizing in order. The enamel is tightly metallized and the metallized enamel-can be used for electric engineering and electronic engineering.

COPYRIGHT: (C)1989,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for metallizing enamel in a highly adhesive manner.

BACKGROUND OF THE INVENTION 2. Description of the Prior Art It is already known to apply a strong gold layer to enamel. This is done by baking a thick paste (DE 65 35 972). Disadvantages here include the high temperatures for baking the metal lily songs and the complicated production of suitable metal pastes.

Said pastes are hardly suitable for metallically bonding several planes of a printed wiring structure. in general,
The paste exhibits low conductivity and the layer thickness (conductor height) is limited to a maximum of 10 μm.

OBJECTS OF THE INVENTION An object of the present invention is to disclose an industrially simple method that enables metal ligatures with strong enamel adhesion.

Means for Solving the Problem This problem is solved by the method described in the claims.

By the method of the present invention, it is possible to firmly adhere and metallize enamel workpieces of any shape, ie, flat and pipe materials, which is extremely important industrially. Furthermore, any metal or metal layer can be applied in each case with the desired quality and thickness by subsequent electroplating;
For the first time, it is possible to form arbitrary metallic structures on the enamel surface.

As the enamel, it is possible to use special glasses which are chemically salts of polysilicic acid and which are bonded to metals such as steel or copper by baking at temperatures below 425°C. The closed structure of this salt is partially opened by alkali and/or alkaline earth oxides. Oxides of multivalent elements such as aluminium, lead, boron, cobalt, nickel, titanium, zinc and/or zirconium or inorganic additives such as sulfides, fluorides and/or arsenides can also be used in the silicic acid network. Introduced into the structure. I can do that.

Enamels may be present in a glassy or partially crystalline structure.

Roughening of the enamel surface is carried out mechanically and/or chemically. Mechanochemical roughening involves first enlarging the enamel surface by sandblasting and then using an etching solution, e.g. ammonium hydrogen fluoride solution, to create narrow grooves in the enamel along mechanical stresses or microcracks. Advantageously, it can be carried out by etching. In general, the required microroughness is achieved by an etching step alone, for which ammonium hydrogen fluoride solutions are particularly suitable, and this may optionally be followed by treatment in acid mixtures. .

Roughening is followed by sonication, which is useful for removing loose material from the enamel surface. This step is absolutely necessary for sufficient adhesion strength of the subsequently deposited metal to the enamel surface. Ultrasonic energy is applied to the workpiece already during or after the etching process, for example in a cleaning process, by immersion in a bath containing an ultrasonic generator. Short residence times of, for example, 5 minutes are sufficient in most cases. Ultrasonication is carried out at room temperature or at a slightly elevated temperature.

The roughened enamel is conditioned with a wetting agent for subsequent activation. Approximately 1% solutions of anionic, cationic and nonionic wetting agents are suitable for this purpose. Both values of the solution are not absolute. Good results can be achieved with a conditioning solution that is 2% sulfuric acid. The optimum conditioning time is 5 minutes. Conditioning is performed at room temperature or at a slightly elevated temperature.

This conditioning is followed by activation of the surface with palladium nuclei. For this purpose, in particular an aqueous solution of a palladium complex with a value of 10.5 is used, so that the enamel surface is not affected by the activator. Activation is carried out at a slightly elevated temperature (approximately 40° C.), and the preferred treatment time is again approximately 5 minutes. After the reduction of palladium ions to metal nuclei, the enamel surface can be chemically metallized in a reduction bath without external current.

According to the invention, the C9 metallized enamel parts are used in electrical and electronic engineering.

Example 1 A steel core coated with glassy cobalt-containing enamel was blown with corundum particles having a particle size of 50 μm to uniformly matt the enamel surface. Subsequently, the wood treated in this way was treated with a 50% solution of ammonium hydrogen fluoride for 5 minutes at room temperature.
It was etched in solution under sonication, rinsed under sonication to remove adhering fluoride and dried at 150°C. The parts were then placed in an acid conditioner at 40°.
Prepared for activation by treatment with C for 5 minutes and activated by immersion in an activator solution for 5 minutes after intermediate washing,
Clean and reduce the Pd''+ on the surface to metal using a suitable reducing agent for 5 minutes and then chemically reduce the copper PI3μ
coated with m.

This metal layer has an adhesion strength of 0.75N/
mrti (peel test).

Example 2 A copper hole plate painted with enamel with a low alkali content is degreased with an alkaline surfactant and exposed to ultrasonic waves for 5 minutes at room temperature.
% ammonium hydrogen fluoride solution and subsequently cleaned under the action of ultrasound. The surface was conditioned, activated and metallized as described in Example 1. The adhesion strength between enamel and copper plating was 1.2N in a peel test.
/It was my friend.

Example 3 The steel hole plate was electrophoretically painted with recrystallized glass ceramic.

This board was first treated with 1% ammonium hydrogen fluoride solution.
The surface was roughened for 10 minutes at 0°C and then worked up in 10% caustic soda under ultrasound. The enamel was conditioned, activated and metallized as described above. After this metallization, the copper/enamel adhesion strength was 0.6
N/I was measured.

Example 4 A metal plate insulated as in Example 6 was first treated under ultrasound for 5 minutes with a mixture of fluoroboric acid and methanesulfonic acid (20%) at room temperature and cleaned. condition adjustment,
Adhesion strength after activation and metallization 1.4 N/
I was measured.

Example 5 A steel perforated plate is painted with recrystallized enamel with low alkali content,
It was subsequently degreased by immersion in an alkaline solution of a detergent and made soluble in a 2% ammonium hydrogen fluoride solution under ultrasound action. After cleaning, conditioning and activating the surface, chemically reducing the 3μ
A copper layer of m thickness was deposited. A photoresist was laminated onto the copper surface and exposed through the original. After development of the resist, the exposed metal surfaces were reinforced with copper by electroplating and a final layer of nickel and gold was applied by electroplating. After removing the resist and removing the base metallization song, the conductor plate thus obtained was fitted with customary interconnect structure elements.

Claims (11)

[Claims] 1. The enamel surface is first roughened, simultaneously with or following this roughening, an ultrasonic treatment is carried out, the surface is then conditioned with a wetting agent, subsequently activated, and then chemically metallized. A metallizing method that provides strong enamel adhesion. 2. 2. The method according to claim 1, wherein the roughening is carried out mechanically and/or chemically. 3. 3. The method according to claim 2, wherein the chemical roughening is carried out by the action of acids, bases or salts. 4. 4. The process as claimed in claim 3, wherein the acid is a mineral or organic acid, the base is an alkali hydroxide or ammonium hydroxide, and the salt is a phosphate or a fluoride. 5. 2. The method according to claim 1, wherein the ultrasonic treatment is performed using an ultrasonic oscillator. 6. 6. The method according to claim 5, wherein the ultrasonic treatment is carried out in a solution. 7. 7. A method according to claim 6, in which an aqueous solution is used. 8. 2. The method according to claim 1, wherein an anionic, cationic or nonionic wetting agent is used. 9. 9. A method according to claim 8, wherein the wetting agent is used in a sulfuric acid solution. 10. Claim 1, wherein the activation is carried out using a palladium complex.
Method described. 11. Metallized enamel produced by the method according to any one of claims 1 to 10.